Improved method for converting residues incorporating deep hydroconversion steps and a deasphalting step

Abstract

The invention concerns a method for converting heavy hydrocarbon feedstocks of which at least 50% by weight boils at a temperature of at least 300° C., and in particular vacuum residues. The feedstocks are subjected to a first step a) of deep hydroconversion, optionally followed by a step b) of separating a light fraction, and a heavy residual fraction is obtained from step b) of which at least 80% by weight has a boiling temperature of at least 250° C. Said fraction from step b) or the effluent from step a) is then subjected to a second step c) of deep hydroconversion. The overall hourly space velocity for steps a) to c) is less than 0.1 h−1. The effluent from step c) is fractionated to separate a light fraction. The heavy fraction obtained, of which 80% by weight boils at a temperature of at least 300° C., is sent to a deasphalting step e). The deasphalted fraction DAO is then preferably converted in a step f) chosen from ebullated bed hydroconversion, fluidised bed catalytic cracking and fixed bed hydrocracking.

Description

[0001]The present invention relates to the conversion of heavy hydrocarbon feedstocks including at least 50% by weight of a fraction having a boiling point of at least 300° C. These are crude oil or feedstocks resulting, directly or after treatment, from the atmospheric and / or vacuum distillation of a crude oil, such as atmospheric or vacuum residues.[0002]It is relatively difficult to enhance these oil residues in value, both from a technical viewpoint and from an economic viewpoint. This is because new regulatory constraints are drastically lowering the maximum admissible content of sulfur in bunker fuel oils (from 3% by weight to 0.5% by weight of sulfur). In addition, the market is in particular demanding fuels which can be distilled at atmospheric pressure at a temperature of less than 380° C., indeed even less than 320° C.PRIOR ART[0003]Patent FR 2 906 814 of the Applicant Company describes a process comprising successively linking together a deasphalting stage, producing a de...

AI Technical Summary

Benefits of technology

This patent describes a way to improve the process for making fuel oil using a catalyst that includes a specific type of clay, called a zeolite. The process involves modifying the process steps to increase the conversion of certain parts of the oil-making process while reducing the overall complexity of the oil. By using specific zeolites, the process can also produce more propylene and isobutene, which are important components of fuel oil.

Problems solved by technology

The large amount of asphalt produced limits the maximum level of overall conversion of the process.

This simple and economical process makes possible thermal integration within one and the same reaction section and makes it possible to obtain a DAO of good quality; nevertheless, the asphalt yields are high, which limits the maximum overall conversion achievable by this process.

The overall conversion of this process is limited by the unconverted heavy effluent.

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